Thermostat for gas-fired water heaters



vlay 6, 1924. 1,492,762

W. STRAUB THERMOSTAT FOR GAS FIRED WATER HEATERS Filed May 2, 1922 Patented May 6, 1924.

STATES WILLARD STRA'UBLOF LOS ANGELES, CALIFORNIA.

TEERMOSTAT FOR GAS-FIRED WATER HEATER/S. l

Application med May 2, 1922. seriai No. 557,959.

To all twhom t may concern.:

Bel it known that I, WILLARD STRAUB, a citizen of the United States, and a resident of Los Angeles, in the county of Los Angeles and State of California, have invented new and useful Improvements in Thermostats for Gras-Fired Water Heaters, of which the following is a specification.

This invention'relates to thermostats for gas fired water heaters, and pertains more particularly to those types of thermostats in which a compound lever acted upon by a thermostatic element, is employed to raise a valve from its seat to allow gas to flow through the valve to a burner. d

The invention has for its principal object to provide a thermostatic valve structure in which friction yis reduced to a practical minimum.

It will be understood in the consideration of the invention that when a lever acts on a rigid vertical valve stem, the free end of said lever invariably moves through `an arcuate path. If the valve stem is properly guided it will of course move -in a straight line. The changing path, of that portion of the lever which acts on the valve stem, lresults in appreciable side thrust and friction between the valve stem and its guide and between said end'ofl the lever and the end of the valve stem. It is therefore 'another object of my invention to provide a thermostat valve structure in which the valve stem is accurately guided while friction between the stem and its guide, and between the stem and lever is reduced to a practical minimum.

A further object of my invention is to provide a valve which will not readily accumulate dirt and foreign matter, and in which a sharp edge valve seat may be employed without resulting in rapid wear.

Still other objects and advantages will appear hereinafter.

I have illustrated my invention by the accompanying drawings in which,

Figure 1, is a view in vertical section of a preferred embodiment of my invention.

Figure 2, is an enlarged view in vertical section of a part of the embodiment illustrated in Fig. 1, which part is hereinafter known as thevalve. e

Figure 3, is a view in bottom elevation of the said valve.

More specifically, reference being had to 5 indicates a thermostat casing which is pro,-`

vided with a horizontal wall 6, dividing the interior space of lsaid casing into an upper chamber 7, andalower chamber 8. An upper wall 9, of the casing is provided *with an internally threaded gas inlet opening 10,

into which is screw threaded a gas pipe 11. i

The lower wall 12, of thecasing is similarly provided with a gas outlet opening: 18,'into which is screw threaded a gas outlet pipe 14, leading -to a burner (not shown),

Wall 6 is provided with yan internally threaded opening 15, into .which is screw threaded a valve seat member 16, and upon said-valve seat memberv a valve disc 16', normally rests. It will be apparent that when.

the valvedisc is raised from its seat communication is established between the upper chamber and the lower chamber, and when this communication is established gas may flow from pipe 11, through the chambers 7 and 8, respectively, to the gas outlet pipe 14.

In the Vlower chamber 8 there is provided a primary lever 17, and a secondary lever 18. These levers are hereinafter jointly known as a compound lever which is in common use in thermostatic devices of the above mentioned type.

An opening 19 is provided in a side wall 20, of the casing, and into this opening is .f

screw threaded a copper tube 21. Said tube is closed at theouter end 22. Said tube being xed relative'to `said casing, end 22 will move toward said casing whenever the tube is cooled and contracts. A porcelain rod 23' is disposed within said tube, one end of i the rod abutting end 22 of the tube. The other end 25 of the rod abuts a' slidable. member 26, which rides on the bottom wall 27 of the casing. n i.

Levers 17 and 18 are each mounted to oscillate on a block 29 by knife edge bearings 30'and 31, respectively. Lever 18 is horizontally'disposed and is formed with a vertically disposed abutment surface 32. Lever 17 is substantially vertically disposed and has a free upper end 33, which abuts the said v abutment surface. In the lower forward portion of lever 17, a concavity 84 ispror-y vided, into which a pointed extension` 35 of the sliding member 26 extends.

It will be apparent now that the weight of the free end 36 of lever 18, together with any weight to whichit may be subjected, will act to hold lever 17 in abutment with annular edge 361 the sliding member 26, and likewise said sliding member will be held in abutment with the porcelain rod.

Such arrangement of parte, including the levers and the valve, is well known and need not be further described herein. The salient feature of my invention resides in the valve disc and valve seat member, each of which l will now describe more in detail.

The valve seat member is of cup-like form and is provided with a sharp upstanding A pluralityV of ports 37 are provided in the valve seat element through which gas may flow when the valve disc is held above'the annular edge 36. A central opening 38 is likewise provided for a purpose apparent hereinafter.

The outside diameter of the valve disc is less than the inside diameter of the annular wall 39 of the valve seat member, so`

Y that gas may flowY freely through the annular space Ll0 thereby provided. i

The valveE disc is of appreciable weigh and carries f a vertically depending rigid valve Ystem 41, which passes through the central opening 38 in the valve seat member and isa sliding lit therein so as to be accurately guided. Said valve stenn carries at its lower end, a lball 42, which is freely mounted therein to rotate universally. Said valve stem may be of any suitable construction, and the ball may be held therein by various means, but inithe form of the invention V illustrated, said valve stem is formed with a bore 48, and the lower end of the stem is peened slightly as at 49, toY retain the ball. A plug 50 is pressed into said bore to limitthe upward movement of the ball. lt will be seen now that l have provided a practically frictionless' end to said valvestem.

The valve disc is preferably faced at the lower side by a washer 51; said washer being of any suitably pliable material, butleather is found to be most satisfactory for this purpose Said washer is held in place by a flange 52, screw threaded into the valverdisc. n 2 i Y Lever 18 acts directly upon the ball end of the valve stem, and it will be apparent that friction in all moving parts of the thermostat is reduced to a practical minimum.l y

The operation of the embodiment illustrated will be apparent from the following l/'Vhen the thermostat tube is heated and expanded it will allow the valve to remain on its seat. The position of the parts when the valve is on its seat is shown in Fig. 1. Should the tube be lowered in temperature it will contract and force the sliding member forward toward lever 17. As a'result the free end of lever 18, which connects with the ball end of the valve.

stem, will be forced upwardly through its characteristic arcuate path. The valve disc TWhile l have shown and described a spe- 'i cific embodiment of my invention I do not limit myself to any specific construction or arrangement of parts, except within the appended claims.

l claim:

1. ln a thermostatic valve,"a thermostat, a valve disc movable tofopen and closed positions and including a depending rigid valve stein, a ball mounted to revolve freely in the lower end of said stem, a substantially horizontally disposedv lever having azfree end disposed to contact. with said ball,-a valve seatelement upon which the valve disc normally rests, and a compound lever operatively disposed between said thermostat and said lever; said valve seat element formed with a bore through which said valve stem passes and is guided thereby to move vertically. Y Y

2. ln a thermostatic valve structure,Y a chambered casing, a horizontal wall dividing the chamber of the casing into an upper chamber and a lower chamber, a perforated valve seat element carried by said wall, a valve disc disposed in the upper chamber resting on said seat element and normally coacting with the valve seat toI close eoinmunication between said chambers, a rigid valve stem depending from said valve disc and passing through said valve seat element into the lower chambe-r'in a manner to be guided thereby so that the valve disc may move vertically only, a ball mounted to revolve freely on the lower end of said stem,

a compound lever in the lower chamber including a lever having a free end coacting with said ball, and a thermostat carried by the casing and extending int-oi the lower chamber to operatively contact with said compound lever.

y3. In' a thermostatic valve' structure, a chambered casing, a horizontal wall dividing the interior of said casing into an upper chamber and a lower chamber, a valve seat element carried by said upper chamber, a valve disc resting on said seat to close communication between said chambers, a rigid depending valve stem carried by said valve disc and extending downward into |the lower chamber; the valve seat element being formed with a bore through which said stem passes so that other than vertical movement of the valve is precluded, a ball mounted to revolve freely in the lower end of said stem, a compound lever in said lower chamber having an end moving through an arcuate path and connecting with said ball, and a thermostat extending into the lower chamber and capable upon contraetion of raising the free end of said lever 5 to raise the said valve disc from the valve seat element.

4. A. thermostatio valve structure, ineluding a thermostat, a lever acted upon by said thermostat so that a ,free end of said lever aseends through an arcuate path When the 10 thermostat Contracts, a valve, a rigid valve stem depending from said valve, and a ballr mounted to revolve freely in the lower end of said stem and disposed to be abutted by said free end of the lever, and means for 15 guiding said valve stem to insure vertical movement, only, ofsaid valve.

WILLARD STRAUB. 

